Android device support is still fairly limited. A couple Samsungs and a single HTC. But certainly better than nothing. I've backed it to get one. My current phone doesn't work with it, but may pick up a Note II.
I decided to back them as well. My Galaxy Nexus phone is made by Samsung and its architecture is similar to the Samsung Galaxies they do support, so I'm gambling that it will also work with mine. For $100 I figure it's worth the risk. Now I just hope the sensor doesn't suck.